The present invention relates to a tape joining device for joining the rear end of a preceding tape to the leading end of a subsequent tape for use in continuously rewinding the two tapes. Such tapes are, for example, liquid penetration preventing seal tapes for covering ends of container blanks of paper-base laminate.
As disclosed, for example, in JP-A-4-105060 (U.S. Pat. No. 5273228), devices of the type mentioned are already known which comprise means for holding two tapes at portions thereof opposed to each other for joining, a fixed bearing member disposed at one of opposite sides of the opposite tape portions and having a bearing surface opposed to the opposed tape portions, a movable pressing member disposed at the other side of the opposed tape portions and having a pressing face and a thermal blade both opposed to the bearing surface, a heater for heating the pressing member, and a movable body having attached thereto the pressing member and movable toward or away from the bearing member so as to press the pressing face and the thermal blade against the bearing surface with the opposed tape portions interposed therebetween.
If the pressing member of the conventional device is not heated sufficiently, the tape is not fully melted for cutting and will be thermally cut improperly. Conversely if the pressing member is excessively heated, the tape will be melted to excess and become fused at a thermally cut portion. It is therefore extremely difficult to control the temperature of the pressing member.